The northern stretch of the Lopburi River loop is called Khlong Chang, while the southern stretch is called today Khlong Wat Tum. Only isolated stretches of water of the loop can be found today.

Khlong Bang Khuat is named after the village Ban Bang Khuat where the by-pass canal had been dug. This village was situated on the east bank of the shortcut canal, just north of Ban Suan Yo and Wat Klang Raman. [1][2]

The canal runs straight south, starting at Wat Tha Yak, passing by Ban Bang Khuat and ending at the mouth of Khlong Wat Tum in between Wat Klang Raman and Wat Pom Raman.

The digging of Khlong Bang Khuat reduced the distance between Ayutthaya and Lopburi with 4 Km. The shortcut canal is around 1.6 Km long.

The canal must have been dug in the ruling period of King Narai (reign 1656-1688) as this sovereign used the City of Lopburi as his seat of power. Nicolas Gervaise (ca. 1662-1729), a young French theological student of the Société des Missions Etrangères residing in Ayutthaya in the late 17th century wrote in the chapter on Lopburi, that "the king has recently had a canal dug, which reduces the distance to only nine or ten leagues." Gervaise stayed in Siam from 1683 till 1686, so I guess the canal must have been dug in the period 1680 - 1685.

Footnotes:

(1) A "khlong lat" is a channel dug across the oxbow of a meandering river to reduce travel distances.